1. Field of the Invention
The present invention relates to swimming goggles, and particularly to swimming goggles with an adjustable head strap.
2. Related Art
Conventional swimming goggles typically have a head strap adjustable with a buckle. The buckle is generally shaped with a couple of loops adjoining to each other. The head strap has two free ends respectively extending through the loops and being overlapped. As the head strap is adjusted in length, friction produced by the overlapped parts of the head strap confines movement, making adjustment cumbersome.
Another fashion of conventional buckles are respectively disposed on left sides and right sides of the lenses frame. Each conventional buckle forms a biasing arm, which biases against denticulate grooves of the head strap, thus the head strap is allowed to be adjusted in a single direction only (namely shortening length of the head strap). To loosen the head strap, the biasing arm is disengaged from the denticulate grooves. However, the conventional buckles are strictly required in manufacture, and therefore lead to high cost. So, it is desired to make buckles of swimming goggles be easily used and manufactured.